Suddenly appeared in my inbox more than 600 old emails as new, at the same time most of emails in the inbox disappeared. Huge gaps lost. How can I fix it?
I have not unified all my email accounts, I keep them separate. Some four months ago, in one of them the Inbox showed emails from 2015 and then... skip directly to 2019. I thought they were all lost but I could check they are all in the server. Somewhat Thunderbird deleted them from my inbox. No worries, it was just a little used mail account... but today it happened again. All of the sudden, the Inbox in one of my accounts showed more than 600 new (unred) emails, but these were as a matter of fact old emails, known to me. At the same time, I checked the inbox and found huge gaps in the email series... jumping months between one mail and another, so... Thunderbird did it again. I have read many troubleshooting advices but did not have the courage to explore because they were all different and was afraid to do some definitive damage to my old, lost emails.
Alla svar (1)
It is possible the Inbox file has become corrupt, this may be due to eg: an Anti-Virus product scanning the file or a lack of maintenance eg: compacting on a regular basis to remove old marked as deleted and hidden emails.
Do not compact the Inbox at this point as it is currently unknown what is going on.
If you have an anti-virus product scanning Thunderbird folders at start up or when downloading email files then stop it scanning or make exempt any Thunderbird file or folder.
Create some suitable folders for organising emails and move all wanted emails from the Inbox into those folders for storage. Ideally, the Inbox should be for new incoming mail and not be used as a general long term storage.
Are you talking about an imap or pop mail account ?